[PATCH v5 34/48] target/nios2: Enable unaligned traps for system mode

[Richard Henderson]

Unaligned traps are optional, but required with an mmu.
Turn them on always, because the fallback behaviour is not
documented (though presumably it discards low bits).

Enable alignment checks in the config file.
Unwind the guest pc properly from do_unaligned_access.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 configs/targets/nios2-softmmu.mak | 1 +
 target/nios2/helper.c             | 4 ++--
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/configs/targets/nios2-softmmu.mak 
b/configs/targets/nios2-softmmu.mak
index 9a372f0717..1e93b54cd1 100644
--- a/configs/targets/nios2-softmmu.mak
+++ b/configs/targets/nios2-softmmu.mak
@@ -1 +1,2 @@
 TARGET_ARCH=nios2
+TARGET_ALIGNED_ONLY=y
diff --git a/target/nios2/helper.c b/target/nios2/helper.c
index 460032adc0..bf40cff779 100644
--- a/target/nios2/helper.c
+++ b/target/nios2/helper.c
@@ -264,8 +264,8 @@ void nios2_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
     CPUNios2State *env = &cpu->env;
 
     env->ctrl[CR_BADADDR] = addr;
-    env->ctrl[CR_EXCEPTION] = FIELD_DP32(0, CR_EXCEPTION, CAUSE, EXCP_UNALIGN);
-    helper_raise_exception(env, EXCP_UNALIGN);
+    cs->exception_index = EXCP_UNALIGN;
+    cpu_loop_exit_restore(cs, retaddr);
 }
 
 bool nios2_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
-- 
2.25.1